Do you have what it takes to make lumber keep time?

[Frank] sent in a link to this fantastic wooden clock. The design was dreamed up by [Clayton Boyer] and he’s got full-sized templates for sale on his site. We’ve marveled at his creations in the past, having featured his useless machine that was made from wooden gears. This “Bird of Paradise” clock steps up the complexity quite a bit, creating a timepiece without a case to show off the beauty of all of those teeth.

We wondered what goes into building one of these yourself. From the FAQ page it seems you could get by with a scroll saw, drill press, Dremel, and sander. That’s the medium-tech method, but you could opt to scan the plans in order to laser cut your parts, or just use hand tools. But in addition to building tips, there’s advice on how to fine tune clocks that don’t want to keep running, thoughts on finishing the wood parts, sanding, tweaking the teeth, and much more. It’s no secret we have a love for digital clock projects, but there’s something very seductive about a design like this that uses no electricity. Don’t miss the clip after the break to see what we mean.

Wooden clocks fascinate me too. I even bought a small scroll saw and practiced a bit but so far I don’t have much progress to report. Another problem to consider, unexpected at first, is availability of decent wood. The type of plywood we have in construction stores here is ok for construction work but is not suitable for fine clockwork. It chips too much.

i think for these you want something more like a 2×4 (or more appropriately a 2×10)
also proportions for the gears is important and you have to remember that wood will shrink
im guessing a normal band saw can work for most the cutting but a dremil or similar tool may be needed to get the finer details

If your town has a woodworking store (like a Rockler or Woodworkers Supply), they carry birch plywood. Sometimes called Finnish plywood too. Its made with more, thinner, and better quality layers than the construction plywood you would find in those huge stores.

A clock is more accurate when the escapement doesn’t put force on the pendulum while it’s in swing, because then the swing is more symmetrical and the period of the pendulum doesn’t depend on the acting torque in the escape mechanism. It’s supposed to give the swinging arm a kick while it’s centered, and let it swing freely with minimum friction otherwise.

That’s why wrist watches have a spring loaded wheel for a pendulum that connects to the escapement with a small slot or a peg on a wheel, so it kinda catches on and throws it one way and then the other.

It looks like the pendulum here is pushing against the torque of the escapement wheel on at least half of the swing because it’s turning it backwards.

That works okay, but only if the torque on the mechanism is sufficiently constant and it never snags on changes in friction on different parts of the rotation.

If you read more on the site (and you should it’s a good read) then you’ll notice he says the clocks are not very accurate, because they are wood they change with the weather, some run off as much as 15 minutes a day. He doesn’t mind because he considers them art instead of timekeeping devices.

Still, the clock could be made much more accurate with a different escapement. It won’t solve the problem with the pendulum arm changing in lenght, and variable friction at the pivot point, but it should make the clock run consistently to within seconds, so you’d only have to adjust it once a week instead.

Those two problems could then be solved by a metal pendulum arm and a metal bearing, or by a careful choice of wood for these parts to make it a truly well engineered timepiece.

I’ve been thinking of a clock with a maze escapement that does just that. It would have a wheel with a square wave slot running on the perimeter and a peg that sticks into it on the end of a lever.

Every time you turn the lever, then peg slides along the wall of the maze and a slanted part on each “tooth” would give it a kick. You can imagine it as a stick that points up and to the side, and when you push it, once over the vertical it snaps into the opposite position.

Now all you have to do is put a notch there that catches a swinging pendulum as it enters, holds it at the middle, and releases it on the other side. It would throw the pendulum into the swing.

I mean, a pendulum in free swing has the same period regardless of the amplitude.

It gets dragged behind a little bit when it releases the escapement at the middle of the swing, but only for a very short moment. Each half-swing is like a separate catch-throw-catch, where only the catching part is affected by the mechanism’s friction.

I’ve built two of Clayton Boyer’s designs so far (I even wrote an Instructable about one of them). It’s a fairly time consuming process. The two main tools you need are a scroll saw and a drill press, along with a set of nice drill bits and good blades.

You could certainly use a laser cutter, but the burn marks left behind would mar the look of the finished piece (IMO).